


Man's Most Insufferable Friend

by bananaskeleton



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Anal Fingering, Collars, Deepthroating, M/M, Plot What Plot/Porn Without Plot, Tenderness, Verbal Humiliation
Language: English
Status: Completed
Published: 2019-10-27
Updated: 2019-10-27
Packaged: 2021-01-04 21:41:16
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,995
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21204521
Author URL: https://archiveofourown.org/users/bananaskeleton/pseuds/bananaskeleton
Summary: Felix jokes about getting Sylvain a dog collar, and Sylvain takes it too seriously because he's a degenerate.





	Man's Most Insufferable Friend

**Author's Note:**

> felix teasing his heterosexual life partner GONE WRONG GONE SEXUAL
> 
> thank you to my friend aspen for betaing this and drawing a [BEAUTIFUL companion piece](https://twitter.com/felixahegao/status/1187212131457994754) for it as it is what motivated me to finish the fic

Felix first spots the damned thing when he and Sylvain are out on the market fetching groceries. Sylvain has, as expected, spent their outing so far ogling women and leaving Felix to handle their errands on his own. The Fraldarius had tried to ignore it, but his annoyance reached a boiling point when Sylvain’s flirting with a married shopkeeper resulted in her rescinding the discount Felix bartered for. In the midst of an angry reprimand directed at his womanizing companion, a leather worker’s stall featuring dog collars catches Felix’s attention.  
  
"Ah, Sylvain. Perhaps I should get one of those things for you. Maybe you’d finally focus on something that isn’t women, if I dragged you by the _neck_."  
  
Sylvain turns to look at the leather worker's stall before snapping his head back to Felix, an incredulous expression on his face.  
  
"Goddess, Fe, you don't really think I'm that preoccupied, do you? I'm sorry. I didn't realize you wanted my attention that badly-"  
  
Felix kicks at Sylvain's shin for that, and though Sylvain's laughter is expected, the tinge of nervousness it possesses is not. Felix stares at the bane of his existence for a quizzical second before deciding to brush it off.  
  
Sylvain is oddly subdued for the rest of their outing.  
  
\---  
  
Two months pass before Felix finds himself rifling through Sylvain's drawers for a book on reason he was told was "_somewhere in there, probably_." Felix considers giving up and just looking for a copy in the library, before noticing Sylvain's bedside drawer contains an object that, by all standards of normalcy, should not be there.  
  
He picks up the dog collar and gapes at it. It’s a simple black, leather stamped with a diamond pattern and dotted with copper rivets at the lines’ intersections. Sturdy and utilitarian, but still possessing its owner’s flair. Felix’s curious examination is cut short when the door to Sylvain's room creaks open and its resident struts in.  
  
"Any luck finding th- Oh. Shit." is all Sylvain croaks out when his eyes land on the object in Felix's hands. Felix doesn’t miss a beat.  
  
"Quite an interesting garment you've got here. Did my comment give you an idea for how you can torment your girlfriends more?" The remark is meant to be teasing but it’s tinged with venom when Felix spits it out. He’s not sure why it even concerns him so much what Sylvain gets up to with girls.  
  
"What- No! It's not like that, Felix."  
  
"What then? Oh... Could it be, you thought you might get me to wear this thing?" Felix holds the collar up with pinched fingers, like it might bite him. "In your dreams, Gautier."  
  
"I didn't- It's- That's not why I got it, Felix!"  
  
“So, if it’s not for a girl or for me- Sylvain, have you got a male lover you haven’t told me about? You-”  
  
"For fuck's sake, Felix, it's for me!"  
  
Sylvain's outburst fizzles out immediately after he realizes those words left his mouth, and Felix watches the redhead's face turn slowly ruddier until the color matches his hair.  
  
Felix coughs.  
  
"Oh."  
  
"Yes. Now since I've told you I'm not using it with anyone else, could you_ please_ just put it back."  
  
It’s probably the polite thing to do, but the sour feeling of what he now realizes was jealousy has been replaced with something like excitement, so he ignores Sylvain and does not put it back.  
  
"It's for you? So, you wear this? Oh, that's rich... Do you make girls drag you around with this thing?"  
  
"I-I told you already it's not for girls. I just... Wear it when I'm alone sometimes."

Sylvain turns his head down and away from Felix as he says that, and Felix wants to punch himself in the face for thinking it's endearing. After a moment of consideration, Felix steps toward Sylvain and holds the collar out for him.  
  
“Put it on. I want to see.”  
  
Sylvain’s head snaps up immediately.  
  
“W-what? Stop it, Felix. Don’t make this any more of a nightmare than it already is,” the man groans.  
  
Sylvain tries to take the collar, but Felix snatches his hand back like a school bully and smirks.  
  
“I’m faster than you. Let me see or I’m making a run for it to show this to Ingrid.”  
  
“You wouldn’t dare,” Sylvain bristles.  
  
“I would dare. Serves you right for skipping training so much.”  
  
The taller man spends a moment glowering at Felix while the other simply shoots a smug look back.  
  
“Fine. I’ll put it on so you can stare at me, then you get the hell out of my room. Give it here.”  
  
Felix’s grin widens as he tuts at Sylvain.  
  
“Oh, no. I’ll put it on you_ myself_. Don’t want you running off with that thing in your hands before I get the chance to properly admire you.”  
  
Sylvain swallows and licks his lips in an unmatched display of composure.  
  
Felix shuffles around to stand behind him, and brings the collar around to Sylvain’s front so he can fasten it at the back. Thankfully Sylvain isn’t decked out in plate armor at the moment, and the breezy shirt he’s wearing gives Felix easy access to his neck.  
  
When the collar comes flush with Sylvain’s skin, Felix hears him let out a wobbly exhale. Felix’s nerves catch up to him, evident when his fingers fumble while trying to pull the leather strap through its buckle. However, focusing on Sylvain’s reaction boosts Felix’s confidence anew.  
  
He finishes buckling the collar on the Gautier’s neck, perhaps a bit tighter than would be completely comfortable. Felix then squeezes a finger under the leather and pulls it firmly to test how it fits. He’s sure Sylvain pants at that. Moving close enough to his friend that his breath is sure to tickle Sylvain’s nape, Felix traces his fingertips along where the collar meets Sylvain’s skin. When he looks up, he sees the man’s mouth hanging slightly open.  
  
Sylvain only chances a look at him once Felix makes his way back to his front, slinking like a weasel pondering how to best pounce on a field mouse. The look on Felix’s face isn’t as smug now as Sylvain expects – his cheeks are dusted a traitorous pink – and Sylvain’s heart thumps in his chest at the realization.  
  
The shorter man stops in front of him, and Sylvain’s arms rise to his chest in response to the sudden proximity before Felix halts the movement, gripping Sylvain’s forearms to feel him relax again after a second. He looks up into Sylvain’s face, searching his expression for something like permission before continuing. Sylvain answers his gaze with a soft, heavy-lidded look that Felix feels he could sink into like thick nectar.  
  
Satisfied, he leans forward and places his open mouth on Sylvain’s Adam’s apple, grazing it with his teeth and sucking lightly. Sylvain only has a second to gasp and choke out Felix’s name before he’s pushed back firmly against the door. Felix grips the man’s arm and shoulder firmly, then tilts his own head slightly up to speak in a hushed voice.  
  
“Is this what you wanted, Sylvain?”  
  
Sylvain’s eyes are unfocused when he looks down at Felix again.  
  
“You got me,” he breathes. Even Garreg Mach’s master playboy couldn’t deny that accusation when Felix need only look down to see the tent formed in his pants. Felix huffs out a laugh.  
  
“How disgraceful. The heir of house Gautier getting off on being treated like a dog.”  
  
Sylvain can’t help biting his lip at the taunt.  
  
“M-maybe.” He swallows. “But you look like you’re into it.”  
  
At that, he pulls Felix against himself and grinds their hips together, one arm around the swordsman’s waist. Felix’s grip on Sylvain tightens momentarily as he gasps at the sudden friction, his head falling against Sylvain’s shoulder as he lets the other man rut against him for a languid minute. But before Sylvain can really begin to lose himself in the rhythm, Felix reaches up to loop a finger through the collar’s metal ring and pushes himself away from the other man - only enough that he’s unable to trap their hips together again. Sylvain groans.  
  
“So eager, Sylvain. I thought dogs were supposed to be obedient.”  
  
A soft “_oh_” leaves Sylvain’s lips.  
  
Felix leans closer again and, still toying with the ring on the taller man’s collar, cranes up to lick the shell of his ear before whispering hotly into it.  
  
“If you want me to treat you like a dog, I can indulge you. But you should commit to the role and do what I tell you to do.”  
  
Sylvain grips Felix’s arms now, holding on with a tremble. After a moment, he manages a whispered “okay.”  
  
“Good boy.”  
  
Felix purrs the phrase, and the lick down Sylvain’s neck that follows makes him whine and buck against the man holding him down again. Felix continues his delicate assault by biting on Sylvain’s pulse point, just hard enough to anchor himself as he sucks a mark into the man’s skin. A wet tongue follows the sting, soothing reddened flesh. Felix can’t resist running his tongue along Sylvain’s neck, across the bottom of the collar, to ply more soft sounds from the man.  
  
But as tempting as it is to tease Sylvain endlessly, Felix is not patient. The heat pooling in his stomach leads him as he places a hand on Sylvain’s shoulder.  
  
“On your knees, Gautier.”  
  
Sylvain collapses in front of Felix like someone kicked his knees in, despite the push of the hand on his shoulder not being firm enough to do anything but suggest the movement. The look Felix receives makes him feel like there’s heavy weight coming to rest on his shoulders, but in a pleasant way. He feels glued in place by that gaze.  
  
“In this position, it would be convenient if you had a leash.”  
  
“Oh. Um, there should be a rope near my equipment.”  
  
Felix nods and turns to rifle through Sylvain’s things again.  
  
“Stay there.”  
  
He hums in satisfaction as he finds what he was searching for and returns with a cotton rope. Tilting Sylvain’s chin up, Felix loops one end through the collar’s ring and ties a practiced knot, pulling the lead to test it out once he’s done. Sylvain keens at the pressure on his throat. His hands look like they’re itching to reach down his pants, but he restrains himself for his handler, and grips the fabric on his thighs instead.  
  
“Felix…”  
  
His name escapes Sylvain’s lips in a sigh.  
  
“Getting impatient?” Felix scoffs, beginning to undo his belt. “Be good.”  
  
Sylvain watches, entranced, as Felix uses the hand not holding his leash to tug down his leather pants, followed by his smallclothes. He’s already hard from Sylvain’s earlier ministrations, and his cock springs free once fabric no longer confines it. Sylvain looks up, eager for direction, but Felix makes no move to bring himself closer to his mouth. Instead he spits into his own palm and wraps around himself, stroking slowly. His other hand holds Sylvain in place by the rope. It’s just too fun to watch Sylvain squirm in place, desperate to get Felix in his mouth.  
  
“Sylvain, what do we say when we want something...?”  
  
“…Please.”  
  
“Please what?”  
  
“Please let me suck you off, Felix.”  
  
Felix supposes he shouldn’t be surprised by how easy that was, and sighs.  
  
“You’re such a slut, Sylvain.”  
  
Sylvain’s ensuing whine transitions to a startled moan when Felix suddenly yanks the rope toward himself and guides the head of his cock into Sylvain’s mouth. The redhead adjusts quickly, positioning his tongue so he can more effectively slick up the underside of the length in his mouth, and this time it’s Felix’s turn to moan.  
  
Sylvain’s eyes close as he works diligently to coat Felix’s cock in spit. He brings a hand up to help cover the length remaining near the base, but Felix swats it away.  
  
“Dogs don’t use their hands.”  
  
That makes Sylvain moan again, more deeply as he sinks further down Felix’s length. Felix’s breath catches when he feels resistance from his dick hitting the back of Sylvain’s throat, but Sylvain ends up having to pull off to catch his breath. Felix resists yanking the rope again and shoving himself down Sylvain’s throat anyway.  
  
The redhead pants heavily without anything to occupy his mouth, his tongue still hanging out to lap at Felix’s head and lave down his length. He looks up at Felix, seeking encouragement.  
  
“Is this… Good, Fe…?”  
  
“Yeah,” Felix breathes before continuing. “Can I fuck your throat?”  
  
Sylvain’s eyes snap shut as he lets out a forceful breath to ground himself. When he opens his eyes again, they seem glazed over.  
  
“Yes,” he answers, breathy with anticipation.  
  
Felix pulls the rope taut again, resting the tip of his dick on Sylvain’s bottom lip.  
  
“Tap out on my thigh if you need me to stop.”  
  
Then his cock is sliding into that wet heat again, now aiming to nestle deeply into it. This time he doesn’t stop when he meets resistance – it makes Sylvain’s eyes water and Felix feels him swallow as he tries to adjust to the thickness. Pushing a little further, Felix’s pelvis is brought flush to Sylvain’s face. He grips Felix’s thighs for anchorage now, lest he be tempted to touch his own dick and likely cum as soon as he brushes it with his fingers.  
  
Felix finds a rhythm sliding in and out of Sylvain’s throat, his movements unhurried but probing. He feels the redhead’s hips buck at nothing on a harder thrust, and decides to place his foot between Sylvain’s thighs. Felix braces an arm against the door behind the man currently at his feet, tensing the leash. The motion pulls Sylvain’s body taut, his and Felix’s silhouette making a bow shape.  
  
It must be hard for him to breathe now, Felix thinks, but Sylvain has made no effort to tap out. Content with that, Felix raises the leg between Sylvain’s thighs to grind the sole of his boot against Sylvain’s clothed dick, making him moan loudly around Felix’s length, his body shuddering.  
  
“Sylvain,” Felix pants, “I can’t believe you waste yourself on girls. Clearly this is what you’re meant for.”  
  
Sylvain lets out another guttural moan at that, his eyes rolling back as Felix continues to slide down his throat. The Gautier’s hands are clawing at the leather of Felix’s pants now, leaving marks. Felix continues to grind torturously with his foot – the pressure not enough to hurt, but enough to show who is in control.  
  
Felix figures he should be responsible and let up, because at the moment, Sylvain looks perfectly content to choke to death on Felix’s dick if he continues. After one last satisfying push, he pulls out of Sylvain’s throat and slackens his hold on the leash. Sylvain slumps against Felix’s thighs, gulping down air.  
  
“Sylvain.”  
  
The Gautier lifts his head from where it’s resting against Felix’s thighs and looks up. His face is a mess – flushed, chin covered in drool and hair disheveled – but he looks pleased.  
  
“Get on the bed. We’re going to do something different.”  
  
“Whoa, Felix… I didn’t realize you had such a strong desire for pleasures of the flesh,” Sylvain teases, but he’s still out of breath and his voice already sounds raspy. That’ll be interesting to explain to the others.  
  
“Says the one who’s about to cum without even taking his clothes off.”  
  
Sylvain laughs more bashfully at that, and Felix has to steady him when he tries to get up on wobbly legs.  
  
“Consider it a compliment, I guess?”  
  
Felix maneuvers the other man to the edge of his bed and then pushes him down, leaning over Sylvain to bring their mouths together.  
  
“Feli- Um-”  
  
Sylvain’s surprised mutter is cut short by Felix’s tongue running along his lips, then into his mouth, tasting the salty combination of his own precum and the redhead’s spit. He seems caught off-guard by the action, probably because they haven’t kissed all that much. Felix thinks it quite amusing if that is what flusters Sylvain, considering their current position.  
  
“Lay on the bed properly,” Felix says and nudges Sylvain’s thigh toward the position he wants.  
  
Sylvain shuffles onto the center of the mattress and gives Felix a curious look.  
  
“What are you plotting, Fraldarius…?”  
  
Felix doesn’t answer, just leans over the other man, takes a hold of his leash again, and brings two fingers to Sylvain’s mouth.  
  
“Open.”  
  
Sylvain’s face goes flushed again and he swallows, but opens his mouth and lets Felix sink his fingers in, against his tongue. Felix rubs fingertips against its pliant surface, coating them in slick fluid. He slips one finger under Sylvain’s tongue to gently clench it between two digits – an indulgent rather than necessary action that draws a sweet sigh out of the redhead.  
  
The swordsman’s ministrations are stopped short when Sylvain, apparently not satisfied with his passivity so far, takes a hold of Felix’s wrist and closes his lips around the digits in his mouth. Sylvain’s eyes meet Felix’s again in a coy gaze, as he makes a show of drawing the fingers out of his mouth, then turning Felix’s palm so he can tongue between the digits, lapping at the skin least hardened by years of sword fighting. Felix already feels hot at the intense eye contact, then Sylvain noses fondly into his palm and kisses it, and Felix thinks he may burn up.  
  
It is somehow less embarrassing when Sylvain returns to running his tongue over Felix’s fingers, coating them, with finality, in what will have to substitute for lubricant at the moment. Felix leans back and rises to his knees so he can remove Sylvain’s pants and boots, unceremoniously tossing them onto the floor, for which Sylvain scowls at him. The expression goes ignored as Felix takes off Sylvain’s smallclothes next, smirking when he sees the wet stain already formed on the fabric and hears Sylvain’s gasp.  
  
Sylvain’s knees are spread by Felix’s calloused hands and the redhead turns away in a surprising show of bashfulness. Felix takes his leash in hand again and pulls to make Sylvain face him again.  
  
“You look nervous. You can tell me to stop, you know.”  
  
Sylvain shakes his head and gives Felix a smile, looking strangely relieved.  
  
“I-I’m good, Fe. Thanks.”  
  
Felix nods and dips his hand lower, finding a ring of muscle and circling it with two wet fingers. Sylvain’s breath hitches, and Felix thinks it’d be nice to hear more, so he presses one digit inside. Sylvain whimpers at that, knees snapping against Felix’s sides, and bites his lip. Felix pulls the leash taut again as he sinks his finger in to the knuckle, beginning to stroke Sylvain’s insides slowly.  
  
“Mh- Ahh… Felix…”  
  
“Is that good..?”  
  
“Y-yeah. Yeah. B-but um, you can put in another.”  
  
Felix’s hand stutters and his finger curls in a way he didn’t intend, and Sylvain cries out, throwing his head back and dropping an arm over his face. His cock drips despite not having been touched since Felix stepped on it minutes ago. Felix figures the Gautier can take a bit of pain and slides a second finger in, making Sylvain yelp again, shuddering.  
  
“Oh Goddess, Felix p-please move-“  
  
A request quickly obliged, as Felix pulls his fingers out to thrust roughly in again, aiming to curl them just so. He keeps up a hurried pace, struggling to imagine what Sylvain must be experiencing as he feels such friction around his fingers. Sylvain seems to have forgotten Felix’s earlier instruction as he palms himself roughly now, a stream of piteous noises coming from his mouth.  
  
“Fe-elix, ah, f- Mm! Th-there, please!”  
  
Sylvain’s eyes go wide, pupils blown when Felix forces his fingers deep and kneads, yanking again at Sylvain’s collar to make him groan deep in his chest. With another few well-aimed movements, the Gautier cums, arching his back off the bed and keening loudly, a vice grip on his cock.  
  
His release splatters messily onto his stomach, the redhead’s chest heaving with breath.  
  
“Goddess, Felix.”  
  
Sylvain looks absolutely debauched. But apart from being obviously fucked-out, there’s a satisfied fondness in his eyes as he grins at the man before him. Felix isn’t sure where to look. He and Sylvain may have just engaged in a deviant sex act, but that doesn’t mean he’s comfortable expressing tenderness towards his best friend yet. Obviously. However as Sylvain comes to and notices Felix’s neglected hardness rubbing against his thigh, his grin turns devious.  
  
“Come here, you.”  
  
“Hey-!”  
  
Muscular arms pull Felix down and wrap around him, Sylvain bringing their mouths together in a fierce kiss. It isn’t lewd like before – craving, yes, but out of a desire for closeness that goes beyond the physical.  
  
“Thank you, Felix.” Soft, unpretending words, said with such a fondness that they threaten to make Felix’s heart burst. “That was amazing. Let me repay you.”  
  
Felix can only gasp as he feels Sylvain’s rough hand on his untended length, strokes immediately firm and heavy.  
  
“You were so good, Fe.” A laugh. “You have no idea how nervous I was when I saw you found that thing. Seems like it all worked out.”  
  
“You’re still a perverted… Bastard… Mmh!”  
  
Another harsh stroke has Felix shaking and jerking in Sylvain’s grip, the taller man keeping an arm wrapped around Felix’s shoulders, while the swordsman rests his head in the crook of the other’s neck.  
  
“And who was it that got off on tormenting this perverted bastard...?”  
  
There’s no denying that, so Felix keeps quiet and lets Sylvain bring him to completion. Well, quiet as he can, because every stroke is dragging some sound out of him now.  
  
“That’s it, Fe… You were so good to me, let me make you feel good too…”  
  
Sylvain follows that up with a wonderful twist of his fingers around the head of Felix’s cock, and it’s just what the dark-haired man needs to spill into Sylvain’s hand and on his stomach, cry catching in his throat. Sylvain continues to pump his hand through the aftershocks, wringing Felix out until his noises begin to sound uncomfortable.  
  
Pulling his hand free, Sylvain wipes it on the sheets before maneuvering Felix into a kiss again. Pliable in his post-orgasmic haze, the swordsman melts into it easily, Sylvain cherishing the unusual complacency.  
  
Of course, Felix soon grumbles something about being sweaty and hot and rolls off Sylvain to slump down at his side, huffing. But not bolting immediately like Sylvain expected him to, so he beams.  
  
“…What are you smiling about.”  
  
“What? I’m not allowed to be happy about being close with someone I care about?”  
  
Felix reddens, but still grunts a “whatever.”  
  
Sylvain takes off the collar and rubs at his neck. A red mark stretches all the way around, and the spot where Felix bit him looks certain to bruise. Felix winces at the sight, and brings his hand toward the abused skin to smooth over it – part shock at his own violence and part an attempt to soothe.  
  
Sylvain pulls him close again, then, and this time Felix doesn’t protest.  
  
“Don’t worry yourself about the marks, Fe. I could heal them if I wanted to. But… I think I want to keep them. As a reminder.”  
  
“A reminder? Of being made to wear a dog collar?”  
  
Sylvain laughs again.  
  
“No. I just want to remember how happy I am being like this, with you. You- you know? It wouldn’t be the same with someone else.”  
  
Felix feels like he just dropped off a height.  
  
“Oh.”  
  
There are many things he thinks to say right now, but all of them are equally embarrassing, so he forces himself to choose one that is slightly less so.  
  
“…I feel the same.”  
  
Sylvain smiles, bright as the sun, and Felix makes a mental note to thank the leather worker that enabled him to witness this.

**Author's Note:**

> hope you all liked babby's first smut huyuuuu


End file.
